https://askubuntu.com/questions/1387154/using-alsa-on-firefo...
https://github.com/i-rinat/apulse
SeaMonkey may be an alternative. It's closer to what I want than Firefox.
Maintaining a browser engine including patching the latest vulnerabilities when someone points Mythos at your code is a really hard problem, my feeling is you need a certain size of organization and funding as your table stakes.
Someone should convince the EU to look into funding a new browser, maybe.